The present invention is directed to a garment for aerodynamic assistance of the propulsion of a rider-propelled wheeled vehicle. The garment is intended for use by recreational, mountain, touring or racing bicyclists. The garment enhances aerodynamic efficiency of the rider when directed into head winds or against cross winds, and provides additional thrust to propel the vehicle and rider, serving as sails, in cross winds or tail winds.
The bicyclist continues to find means and devices to propel him faster or to maintain speed with less effort. While this may be attained by using lighter materials, such as titanium, aluminum, specialty steel frames and carbon fiber, the only other alternative is to enhance the aerodynamic efficiency of the rider and bicycle. Such devices as aero handle bars, aero frames, aero wheels, aero brakes, aero cable routing, aero helmets, aero skin suits and the like have been developed to accomplish this. However, in spite of the dedication of technology and investment on items to improve the aerodynamics of the bicycle and to deal with the problem of weight, the rider is still the greatest source of aerodynamic drag. Typically the rider represents about 64% of the aerodynamic drag and the bicycle represents 21%, with the remainder being due to wheels, spokes, tires, rolling and frictional resistance.
An essential factor in relation to the physics governing cycling is that the total resistance to forward movement on a bicycle is a direct function of the square of the speed. Thus, doubling a rider's speed increases the total resistance to forward movement four-fold. Furthermore, there is a disproportionately greater increase in total resistance when a cyclist increases his speed, for example, from 40 to 42 kph as compared to increasing his speed from 20 to 22 kph. Air resistance is the primary element of the total resistance that causes this increase in total resistance, since at such speeds difference in frictional components of resistance is small. For example, at a 10 kph riding speed the air resistance contributes less than 20% of the total resistance to forward movement encountered by the cyclist. At speeds of 20 and 40 kph air resistance increases to 54% and 82%, respectively, of the total resistance, with rider drag being the major component of the total resistance and of the total air resistance.
To deal with the aero dynamic drag of the rider, there are aero skins, aero glasses and aero helmets, as well as improved rider aerodynamic positions with or without using aero bars.
The present invention provides a method for not only improving the aerodynamics of the rider, but also to utilize the prevailing winds to assist in the propulsion of the bicycle.